What is Class 1B antiarrhythmics?
Class IB antiarrhythmics suppress automaticity of conduction tissue by increasing the electrical stimulation threshold of the ventricle and His-Purkinje system and inhibiting spontaneous depolarization of the ventricles during diastole through a direct action on the tissues.
When do you use Class 1B antiarrhythmics?
A class 1B antiarrhythmic agent used in the treatment of documented ventricular arrhythmias that warrant treatment. An orally active class 1b antiarrhythmic agent that interferes with cardiac sodium channels and typically used to treat ventricular arrhythmias. Aprindine is a cardiac depressant used in arrhythmias.
Which of following antiarrhythmic drug is Class 1b agent?
Ib -Lidocaine, phenytoin, mexiletine (depress phase 0 selectively in abnormal/ischemic tissue, shorten repolarization)
Which class is antiarrhythmic 1A?
Antiarrhythmics, Class Ia
| Drug | Drug Description |
|---|---|
| Disopyramide | A class 1A antiarrhythmic agent used to treat life-threatening ventricular arrhythmias. |
| Quinidine | A medication used to restore normal sinus rhythm, treat atrial fibrillation and flutter, and treat ventricular arrhythmias. |
Which drug is considered a Class 1A antiarrhythmic drug?
How are Class Ic drugs used to treat arrhythmias?
Class Ib drugs are used for the suppression of ventricular arrhythmias (ventricular premature beats, ventricular tachycardia, ventricular fibrillation). Class Ic antiarrhythmic drugs Class Ic drugs have slow kinetics; they express their electrophysiologic effects at all heart rates.
How does Class 1 antiarrhythmic suppress abnormal automaticity?
Class 1 antiarrhythmic agents can suppress abnormal automaticity by decreasing the slope of phase 4, which is generated by pacemaker currents. The mechanism for this is not understood and is unrelated to blocking fast sodium channels.
What are the different types of antiarrhythmic drugs?
Antiarrhythmic drug classes: Class I – Sodium-channel blockers Class II – Beta-blockers Class III – Potassium-channel blockers Class IV – Calcium-channel blockers Miscellaneous – adenosine. – electrolyte supplement (magnesium and potassium salts)
What is the effect of Class III antiarrhythmic drugs?
Class III Antiarrhythmic Drugs. Thus, the capacity of all cardiac tissues to transmit impulses at high frequencies is reduced, but conduction velocity is not significantly affected. Because the action potential is prolonged, rate of automaticity is reduced. The predominant effect on the ECG is QT-interval prolongation.